* {
    margin: 0;
}

html,
body {
    height: 100%;
}

body {
    display: flex;
    flex-direction: column;
}

header {
    border-bottom: 1px solid #ccc;
    padding: 20px;
    margin-bottom: 30px;
    flex-shrink: 0;
}

.body {
    display: flex;
    margin-bottom: 20px;
    flex-grow: 1;
}

.sidebar {
    width: 200px;
    flex-shrink: 0;
    flex-grow: 0;
}

.main {
    flex-grow: 1;
}

footer {
    height: 50px;
    flex-shrink: 0;
    flex-grow: 0;
    padding: 20px;
    text-align: center;
}